Method of dispensing a liquid reagent

• US 5,741,554 A
• Filed: 07/26/1996
• Issued: 04/21/1998
• Est. Priority Date: 07/26/1996
• Status: Expired due to Term

• Current Assignee: Bio Dot Incorporated
• Original Assignee: Bio Dot Incorporated
• Inventors: Tisone, Thomas C.
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): CHEN, BRET P
• Application Number:
  US08/686,957
• Time in Patent Office: 634 Days
• Field of Search: 427/421, 427/424, 427/8
• US Class Current: 427/424
• CPC Class Codes: B01L 3/0265 using valves to interrupt or meter fluid flow, e.g. using solenoids or metering valves
• CPC Class Codes: B01L 3/0268 using pulse dispensing or spraying, eg. inkjet type, piezo actuated ejection of droplets from capillaries
• CPC Class Codes: B05B 1/3053 the actuating means being a solenoid
• CPC Class Codes: B05B 12/06 for effecting pulsating flow nozzles, spray head or outlet with means for generating a discharge of pulsating nature B05B1/08
• CPC Class Codes: B05B 17/0607 generated by electrical means, e.g. piezoelectric transducers
• CPC Class Codes: B05B 7/066 with an inner liquid outlet surrounded by at least one annular gas outlet
• CPC Class Codes: B05B 7/2489 an atomising fluid, e.g. a gas, being supplied to the discharge device B05B7/2402, B05B7/2483, B05B7/262 take precedence
• CPC Class Codes: B05B 9/0413 with reciprocating pumps, e.g. membrane pump, piston pump, bellow pump B05B9/0409 takes precedence
• CPC Class Codes: G01N 2035/1041 Ink-jet like dispensers

Abstract

A method for dispensing precise quantities of reagents is disclosed including the steps of providing positive displacement syringe pump in series with a dispenser, such as a solenoid valve dispenser. The pump is controlled by a stepper motor or the like to provide an incremental quantity or continuous flow of reagent to the dispenser. The dispenser is operated in accordance with predetermined parameters to dispense droplets of reagent onto a target substrate at the metered flow rate.

Claims

1. A method for forming a diagnostic test strip comprising the steps of:

movably transporting a receptive membrane;

metering a predetermined quantity or flow rate of liquid reagent using a positive displacement pump;

operating a dispenser to mix said metered quantity or flow rate of liquid reagent with air to form an aerosol mist which is deposited on said receptive membrane; and

regulating the metering of said predetermined quantity or flow rate of liquid reagent and the transporting of said receptive membrane such that the reagent density is controlled in terms of volume of reagent per unit length substantially independently of the particular flow characteristics of said liquid reagent.

2. A method for dispensing a liquid onto a substrate comprising the steps of:

movably transporting the substrate;

metering a predetermined quantity or flow rate of said liquid using a positive displacement pump;

supplying said metered quantity or flow rate of said liquid to an air brush dispenser to form an aerosol mist which is deposited on said substrate; and

regulating the metering of said predetermined quantity or flow rate of said liquid and transporting of said substrate so that the density of said liquid deposited on said substrate is independently controlled in terms of volume per unit length of said substrate.

3. A method for dispensing a liquid onto a substrate comprising the steps of:

movably transporting said substrate;

adjusting a positive displacement pump to meter a predetermined flow rate of said liquid;

adjusting the opening and closing time of a valve in accordance with a predetermined frequency and duty cycle to allow said liquid to form droplets of a desired size and/or frequency at said predetermined flow rate;

depositing said droplets upon said substrate; and

regulating the metering of said predetermined flow rate of liquid and transporting of said substrate so that said liquid is dispensed in predetermined quantities of volume per unit length of said substrate substantially without being affected by the particular operating parameters of said valve.

4. A method for dispensing a liquid onto a substrate comprising the steps of:

movably transporting said substrate;

metering a predetermined quantity or flow rate of said liquid using a positive displacement pump;

operating a dispenser including opening and closing a valve to form airborne droplets of said liquid;

depositing said droplets of liquid upon said substrate;

regulating the metering of said predetermined quantity or flow rate of liquid and transporting of said substrate so that the density of said liquid deposited on said substrate is controlled in terms of volume per unit length and so that the quantity and/or flow rate of said deposited droplets are metered in accordance with predetermined amounts.

5. A method for dispensing a liquid reagent onto a receptive membrane comprising the steps off;

operating a liquid reagent dispenser, including a positive displacement pump, to meter a predetermined flow rate of liquid reagent;

adjusting said reagent dispenser to form droplets of a desired size, frequency and/or spray pattern at said predetermined flow rate;

depositing said droplets of liquid reagent upon said receptive membrane;

providing relative movement between said receptive membrane and the formed droplets;

controlling the metering of said predetermined flow rate of liquid reagent and relative movement between said receptive membrane and said droplets so that the reagent density is controlled in terms of volume per unit length.

6. The method described in claim 5 wherein said droplets are in the range of about 1-4 nanoliters.

7. The method described in claim 5 wherein said droplets form an aerosol mist wherein each droplet is smaller than about 1 picoliter.

8. A method for dispensing predetermined quantities of liquid onto a substrate comprising the steps of:

selecting a desired flow rate of liquid to be dispensed by a positive displacement pump;

adjusting said dispenser to form droplets of a desired size, frequency and/or spray pattern while maintaining said desired flow rate;

metering said flow rate of said liquid to form said droplets;

depositing said droplets of liquid upon said substrate.